[PATCH v2] virtio: fix reference leak in register_virtio_device()

[Ma Ke]

Once device_add(&dev->dev) failed, call put_device() to explicitly
release dev->dev. Or it could cause double free problem.

As comment of device_add() says, 'if device_add() succeeds, you should
call device_del() when you want to get rid of it. If device_add() has
not succeeded, use only put_device() to drop the reference count'.

Found by code review.

Cc: stable@xxxxxxxxxxxxxxx
Fixes: f2b44cde7e16 ("virtio: split device_register into device_initialize and device_add")
Signed-off-by: Ma Ke <make_ruc2021@xxxxxxx>
---
Changes in v2:
- modified the bug description to make it more clear;
- changed the Fixes tag.
---
 drivers/virtio/virtio.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/virtio/virtio.c b/drivers/virtio/virtio.c
index b9095751e43b..ac721b5597e8 100644
--- a/drivers/virtio/virtio.c
+++ b/drivers/virtio/virtio.c
@@ -503,6 +503,7 @@ int register_virtio_device(struct virtio_device *dev)
 
 out_of_node_put:
 	of_node_put(dev->dev.of_node);
+	put_device(&dev->dev);
 out_ida_remove:
 	ida_free(&virtio_index_ida, dev->index);
 out:
-- 
2.25.1